What is paravirtualization


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Paravirtualization refers to the simple virtualization technique that can be used to basically improve the performance in a guest operating system by giving sort of a direct link between the virtual machine and the underlying physical hardware

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What is paravirtualization

  1. 1. Author: Panait Robert Email: braxis@virtualizationsoftwares.com URL : http://www.virtualizationsoftwares.com FB : https://www.facebook.com/VirtualizationSoftwares TW: https://twitter.com/virtsoftwares What is Paravirtualization ?The term Paravirtualization may be new to you, but the fact is that ithas been around for a fairly long time. Paravirtualization has existedsince 1972 in IBMs old VM operating system where it is calledDIAGNOSE code", and it is also present as a distinct feature in theParallels Workstation operating system under the name "hypercall".In truth, while there are several different terms by which it has beenknown over the years, paravirtualization refers to the simplevirtualization technique that can be used to basically improve theperformance in a guest operating system by giving sort of a direct linkbetween the virtual machine and the underlying physical hardware.Before a guest operating system is installed inside a virtual machine, it isrecompiled in order to achieve the enhancement of the virtualizationtechnology through paravirtualization.With paravirtualization, any and all software that is running on avirtual system will be able to work directly on the underlying physicalsystem hardware. That is, the software itself on the virtual machinesguest operating system will be able to make calls on the hardwaredirectly instead of relying on just the virtual machine to make thenecessary calls for it. Because of this, performance is increased withoutthe need to sacrifice any computing power.
  2. 2. Paravirtualization falls under the three main types of hardwarevirtualization. As you may already know, hardware virtualization alsocommonly referred to as platform virtualization, is the creation of avirtual machine that performs as if it were an actual computer that hassome kind of an operating system installed on it.Hardware virtualization allows software to be installed and run onvirtual machines that are separated from underlying physical hardwareresources. A computer that is running a version of the MicrosoftWindows operating system might have a virtual machine on it that isrunning a version of the Gentoo Linux operating system. That is onebasic example of hardware virtualization at work.The three types of virtualization in hardware and these are fullvirtualization, partial virtualization, and paravirtualization.
  3. 3. VirtualizationIn full virtualization, there is almost a complete model of the underlyingphysical system resources that allows any and all installed software torun without modification.Partial virtualiationIn partial virtualization, not everything in the target environmentbecomes simulated. Not all software programs installed on the guestoperating system can run unmodified.
  4. 4. ParavirtualizationFinally, theres paravirtualization, which as explained above, isessentially a way to improve performance by having a software interfaceworking between the virtual machine and the underlying physicalhardware system itself.Intel (Intel VT - IVT ) and AMD (AMD-V) have both released hardwarevirtualization technology to facilitate the running of hardwarevirtualization on computers. This technology has been designed to boostthe power of the hypervisor.Although these two pieces of hardware virtualization technology areseparate and independent, they perform broadly the same function. Asincreasing numbers of modern computers are sold with incorporated
  5. 5. hardware virtualization technology, more powerful CPUs willcontinually be developed to allow for better creations of simulatedenvironments.In a virtual machine, there is something called the hypervisor, which isbasically the visual interface installed on a real machine that takes careof operations on the virtual counterparts. Now in most cases, thehypervisor will not be accessible to the instances in a virtual machine.Instead, it can only be accessed by those who actually have access to thereal machine itself. And even if it is possible to gain access to thehypervisor on a virtual system, there will often be severe limitations towhat can be done with it.
  6. 6. In order to avoid going through the virtual operating system for access tohardware whenever it is needed, one can rely on paravirtualization.What paravirtualization does is allow users on a virtual system to avoidgoing through the virtual fluff and call on the underlying physicalhardware resources directly. This helps save so much time andcomputing resources.How exactly does paravirtualization improve overall performance ?Paravirtualization can minimize system overhead and really optimizeoverall performance due to the fact that it can support the use of virtualmachines that would otherwise be underutilized in the two other formsof hardware virtualization mentioned earlier.Though it has many advantages, paravirtualization isnt withoutlimitations. For instance, paravirtualization requires the guest OS to becustomized for the virtual machine monitor which it will run on top of.That is, in order to take advantage of paravirtualization, you first have tomake certain preparations on the virtual system as well as on thephysical system itself. You usually won’t find it included in standardinstallations. However, some software companies do provide add-onsthat give the necessary abilities for all of this to become a reality.
  7. 7. If you liked this article you can find more posts about this niche onhttp://www.virtualizationsoftwares.com , a site dedicated entirely tovirtualization software, where everyone will find general informationabout the matter, that will help potential clients to find the perfectprogram as well as reviews for the products of the main players of thevirtualization software market.Related Articles :What is Hardware Virtualization ? What is virtualization software?What is Hypervisor ? What is Xen Virtualization ?